环锭纺竹节纱捻度分布及其对强力的影响

Twist distribution of ring spun slub yarn and its influence on the yarn strength

根据环锭纺竹节纱在加捻过程中的扭应力分布状况,采用杆件扭转模型,建立了竹节纱加捻扭转的数学模型。借助这一模型分析了竹节纱的4个参数(基纱直径、竹节直径、竹节间隔以及竹节长度)对捻度分布的影响。分析表明,竹节部分的捻度总小于设计捻度,主要受竹节直径与基纱直径比值的影响,比值越大,减少越明显;基纱部分的捻度总大于设计捻度,主要受竹节长度与竹节间隔比值的影响,比值越大,增加越明显。在捻度分布研究的基础上,分析了竹节纱捻度分布对强力的影响,并进行了实验验证。一般情况下,竹节部分的捻度下降对强力的影响不及竹节部分纱线截面内纤维根数增多的影响,因而竹节部分的纱线强力高于基纱部分的强力,竹节纱强力的大小与捻度和基纱捻度相同的普通纱强力极为接近。

A mathematical model of twisting torsion of the slub yarn has been developed through the pole torsion model based on the distribution of the torsional stress on the ring-spun slub yarn during twisting. The influence of four parameters （ basic yarn diameter, slub diameter, slub space and slub length）on the distribution of twist was analyzed using this model. The results showed that the twist of the slub is always less than the designed, which is chiefly influenced by the ratio of the slub diameter to the basic yarn diameter, and increase of the ratio will decrease the twist; while the twist of basic yam is always more than the designed, which is mainly influenced by the ratio of the slub length to the slub space, the increase of the ratio will increase the twist. The effect of the distribution of twist on the yarn strength was also analyzed, and verification experiment was performed. In general, the strength of the yarn is influenced more by the increased fiber quantity in the yam than by the decrease of the slub twist. Therefore, the strength of the slub is higher than that of the basic yarn. The strength of the whole slub yam is very close to that of the common yarn with the same twist as the basic yarn.